Marathon's Symbiosis update will let players tackle a three-run PvE series alone or with a crew, without rival players interrupting. The December 8 update also adds a separate 3v3 Deathmatch beta where permanent loadouts are not at risk.
The November 10 announcement details Expedition, the PvE-only mode launching in Phase 1. Combat and environmental challenges remain, and players can use Flash Boosts to adjust their builds during a run.
That separates Expedition from Marathon's usual mix of enemy encounters and competing crews. Bungie's official game site describes an extraction loop in which players scavenge equipment, escape with it and risk that gear on their next outing. Expedition removes the PvP threat; the announcement does not spell out its gear-loss or progression rules.
Deathmatch takes the opposite approach by focusing on short, points-based fights between two crews. It is explicitly an experimental beta, not a replacement for the extraction game.
Perimeter expands, with Bishop and two new weapons
Symbiosis also changes the terrain of Tau Ceti IV. Fungal growth and alien life have spread through Perimeter, opening the underground Burrows and submerged Reservoir as playable areas. The Tick Queen waits beneath the surface.
The new Bishop Runner shell is a fast, blade-wielding robot. Its arrival accompanies the V17 Flamethrower, a short-range area-denial weapon, and the Maverick, a revolver with a hand-cannon feel.
Away from those encounters, a new social space called Limbo gives Runners firing ranges to test weapons and gear, alongside a dueling pit for challenging each other.
Open Play Week runs December 8-15, starting alongside Symbiosis. The update arrives for all players on December 8. Marathon is available on PS5, Xbox Series X|S and PC, with cross-play and cross-save support. Online play requires an internet connection and a paid console subscription; cross-save requires a compatible game copy on each system and platform accounts linked to Bungie.net.